title: The influence of margin location on the amount of undetected cement excess after delivery of cement-retained implant restorations.
abstract: OBJECTIVE
  The aim of this study was to evaluate the amount of the residual cement excess after cementation and cleaning of implant-supported restorations with various positions of the margins.
  
  
  METHODS
  Twenty-five casts with embedded implant analogs and flexible soft-tissue imitation were used in the study. Individual abutments with different position of the margin - from 1 mm supragingivally to 3 mm below the gingival level - were modelled and divided equally into five groups. The same amount of polished metal crowns was luted to prosthetic abutments, excess cement was cleaned and the restorations were removed for evaluation of the undetected cement remnants. All quadrants of each specimen were photographed for calculation of the ratio between the cement remnants area and the total specimen area using Adobe Photoshop. Afterwards, cement remnants were cleared from each specimen and weighed with analytical balances.
  
  
  RESULTS
  The measurements in all the groups consisted of (1) the relation between the cement remnants area and the total area of the specimen; and (2) cement excess weight in grams after cleaning: group 1 (0.0111 ± 0.021; 0.0003 ± 0.0001 g); group 2 (0.0165 ± 0.019; 0.0008 ± 0.0003 g); group 3 (0.0572 ± 0.028; 0.0013 ± 0.0005 g); group 4 (0.1158 ± 0.054; 0.0051 ± 0.0013 g); and group 5 (0.1171 ± 0.059; 0.0063 ± 0.0021 g). Results showed significant increase of undetected cement quantity, as the restoration margins were located deeper subgingivally, using weighting (P=0) and calculation of proportion (P=0). There was a significant correlation between evaluation techniques (r=0.889; P=0).
  
  
  CONCLUSIONS
  The amount of residual cement after cleaning increased as the restoration margins were located more subgingivally.
authors.affiliation: Vilnius Research Group, Vilnius, Lithuania Vilnius Implantology Center, Vilnius, Lithuania. linktomo@gmail.com
authors.forename: Tomas
authors.initials: T
authors.lastname: Linkevicius
authors.forename: Egle
authors.initials: E
authors.lastname: Vindasiute
authors.forename: Algirdas
authors.initials: A
authors.lastname: Puisys
authors.forename: Vytaute
authors.initials: V
authors.lastname: Peciuliene
mesh_terms: D002484:Cementation / Q000379:methods*; D003442:Crowns; D000044:Dental Abutments; D003735:Dental Casting Technique; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D006801:Humans; D018709:Statistics, Nonparametric; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*